SW Michigan Fruit Update
August 3, 2004
Weather
July was dry and cooler than normal. High temperatures were usually below 80 and lows below 60. Soils are dry. Soils temperatures are in the mid 70s. This week’s weather forecast is for warmer weather with a chance of showers or thundershowers.
Southwest Michigan Growing Degree Day Totals March 1, 2004 through August 1, 2004 |
|||
Location |
GDD 42 |
GDD 45 |
GDD 50 |
2531 |
2177 |
1635 |
|
Bainbridge |
2587 |
2227 |
1680 |
Lawton: |
2606 |
2239 |
1716 |
Hartford |
2469 |
2080 |
1541 |
Grand Junction: |
2646 |
2252 |
1699 |
2269 |
1928 |
1414 |
|
Tree fruit
Fruit continue to size well. Fruit flies are out in cherries, apples and blueberries. Japanese beetles are common in Southern Michigan. Leafhopper and mite numbers are building. Codling moth trap catch is up. Insect trap catches for some pests are down. Oriental fruit moth trap catch numbers are low. The second-generation flight of redbanded leafroller and obliquebanded leafroller is finished. All of these pests should pick up back soon.
Peach harvest is underway. Size is excellent. Split pits, which were common in early varieties can still be found. The second generation of Oriental Fruit Moth has ended, but the third generation should begin flight soon (1900 GDD). Oriental Fruit Moth Biofix was April 29 at 300 GDD 45. We are at 1877 GDD-45 since Biofix and egg hatch should end at 1950 GDD. We are picking up about 20 to 25 GDD a day.
In Cherries, cherry leaf spot is common and many orchards have lost most of their leaves. Bravo is an excellent protectant for the post harvest season. We have had only a few infection periods since harvest ended.
Plums are colored. Harvest of early European varieties has begun. Growers should protect against apple maggot, which will attack plums near harvest. Leafhopper damage, both white apple leafhopper (white stippling of leaves) and potato leafhopper (curled leaves with yellow edges) are easy to find. European red mites are causing stippling in some orchards.
Apple growers are harvesting summer apple varieties. Growers should have fungicides in their cover sprays to reduce sooty blotch and flyspeck. Fire blight is common in the region and severe in some orchards.
Codling moth trap catches are up. Biofix on May 7 at 235 GDD base 50, our current total is 1635 GDD, and we are at 1400 GDD after Biofix. Egg hatch for the second-generation codling moth is underway. The third generation flight of Oriental Fruit Moth should start late next week. We are catching apple maggot in low numbers. I would expect maggot catches to increase after a rain. There are few leafroller larvae feeding on the shoot tips. Obliquebanded leafroller trap catches are low. The second-generation flight should be starting soon. The second-generation flight starts at 2100 base 42. We should be at peak emergence and peak egg hatch for this pest 2300 GDD base 42. The third flight of redbanded leafroller should start at 1700 GDD base 45. New spotted tentiform leafminer mines are appearing. The third generation of this pest emerges in mid August. White apple leafhopper larvae are out. Some apple orchards are bronzing from European red mite. For European red mite the treatment threshold for this pest is 7.5 mites/leaf.
In Pears, second generation codling moth can attack pears. Pear psylla numbers are building in some orchards.
Small fruit
In Blueberries, Bluecrop harvest is ending and Jersey harvest is well underway. Both blueberry maggots and Japanese beetles are out. Tussock moth adults are being caught as well as a few leaf roller adults. Tussock moth larvae are also being found. Low numbers of blueberry aphids can be found in the bottoms of the bushes. Alternaria is the main fruit rot showing up on the fruit. Growers should protect the fruit. Birds eating the fruit are a major problem.
Grapes are beginning veraison. Niagara harvest is scheduled to begin September 7 with Concord harvest following 10 days later. The second generation of grape berry moth is flying and stings in fruit can be found. Growers should be scouting hot spots and the edges of their vineyards for stings and other signs of recent berry moth activity. Grape leafhopper numbers are building. Phomopsis symptoms are easy to find in most grape vineyards. Downy mildew is showing up in susceptible varieties and growers should be applying protectants such as Ziram or Prophyt as an eradicant to reduce the spread of this disease.
Southwest Michigan Grape Growing Degree Days form April 1, through Sunday August 1, 2004. |
|
Location |
Grape GDD |
1587 |
|
Bainbridge |
1632 |
Lawton: |
1624 |
Hartford |
1495 |
Grand Junction: |
1645 |
1377 |
|
In Strawberries, now is a good time to fertilize new growth in strawberry new growth looks good
Summer Raspberry harvest is over. The old floricanes are yellowing and should be pruned out. Japanese beetle and potato leafhoppers are common in brambles and should be controlled. Fall bearing raspberries are flowering and some early fruit is being harvested.
